This invention relates to support structures for checking and repairing rotatable objects, and more particularly to support structures which can support large-sized or gigantic rotors such as turbine rotors for power generators or blower fans in the checking or repairing operation.
Conventionally, for example, the levelling of a turbine for power generator which is mounted on a base frame is conducted such that the roll-support bases, which rotatably support the respective ends of the turbine rotor, are adjusted for levelling thereof by rotating adjusting bolts or levelling bolts. However, the foundation on which such roll-support bases are mounted is not generally provided with the rigid supports. Therefore, even when accurate horizontal levelling of the roll support bases is achieved before the turbine is mounted on the roll support bases, once the turbine is bridged and held by the roll support bases, the floor surface of the foundation is distorted or warped resulting in poor levelling. Such poor levelling produces a considerable degree of thrust on the supporting rolls on the roll support bases, and such thrust is further enhanced by the deflection of the rotor shaft which is caused by the weight of the turbine. Thereby, when the turbine is rotated on the axis thereof along with the rotation of the support rolls, the turbine moves in an axial direction along with the rotation thereof so that the checking or repairing of the turbine becomes extremely difficult and cumbersome. Furthermore, in an extreme case, the rotor shaft of the turbine suffers partial intensive frictional wear resulting in rupture of the rotor shaft. This makes the checking or repairing operation extremely dangerous. For preventing the occurrence of such a situation, further or secondary levelling must be performed after the mounting of the turbine on the roll support bases and such relevelling necessitates a great deal of time and labor.
Accordingly, it is an object of the present invention to provide support structures for checking and repairing a rotor which can resolve the aforementioned defects of conventional support structures and which can readily, accurately and automatically provide the best support condition for the roll support bases.
In summary, the present invention discloses a support structure for checking and repairing a rotor comprising a pair of parallel spaced-apart rotor support rolls rotatably supporting one end of the rotor, a roll support base mounting a pair of rotor support rolls thereon and an adjustable surface plate disposed below the roll support base for supporting the roll support base and a base frame disposed below the surface plate for supporting the surface plate, wherein the improvement is characterized in that a spherical support mechanism is disposed between the roll support base and the adjustable surface plate so as to allow the roll support base to tilt in any radial direction on the spherical support mechanism. Due to the spherical support mechanism, the rolls on the support bases can uniformly support both ends of the impeller rotor without inparting any thrust to the rolls even when horizontal levelling is not achieved.